Abstract

The recovery of spent lithium iron phosphate batteries (LFPBs) has significant meaning in resource recycling and environmental protection. In order to investigate the effect of thermal treatment on the spent LFPBs cathode plate, in this paper, the thermogravimetric-differential scanning calorimetry (TG-DSC) of spent LFPBs cathode plate is researched. TG-DSC results indicate that two stages of weight losses and a stage of weight gain appear during the heating process with a weight change of −3.7, +1.0, and −2.4%. DSC curve showed two endothermic peaks at 165.6, 657.5 °C and two exothermic peaks at 475.6, 532.2 °C. XRD results indicate that LiFePO4 is oxidized to Li3Fe2(PO4)3 and Fe2O3 during the heating process and the electrode material could be easily separated from aluminum foil due to the pyrolysis of the binder. SEM-EDS results indicate that the agglomeration degree of cathode powders decreased after the TG-DSC test, the mole fraction of C and F decreased from 23.98 and 7.03% to 1.06 and 0.32%, which was due to the pyrolysis of binders and conductive additive.

Keywords

Notes

Acknowledgements

This work was funded by the Research Fund Program of State Key Laboratory of Rare Metals Separation and Comprehensive Utilization (No. GK-201806) and Anhui Province Research and Development Innovation Project for Automotive Power Battery Efficient Recycling System for which the authors are grateful.